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Rogerio Gribel - One of the best experts on this subject based on the ideXlab platform.
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growth and survival over ten years of brazil Nut Trees planted in three anthropogenic habitats in northern amazonia
Acta Amazonica, 2021Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:ABSTRACT We examined the growth and survival of Brazil-Nut Trees, Bertholletia excelsa (Lecythidaceae) under different environmental conditions and levels of canopy openness within experimental plantations in the Trombetas River valley, in northern Brazil. We planted 144 seedlings in three anthropogenic habitats with different levels of sunlight exposition: crop field (100% canopy opening), shrub fallow (20-80% canopy opening) and Brazil-Nut forest (< 10% canopy opening). We measured plant height and diameter annually and recorded mortality and resprouting over ten years. The performance of B. excelsa differed significantly among habitats, with the highest growth rate observed at the highest level of canopy openness (crop field). Survival was highest in crop field (85%) and shrub fallow (63%) and lowest in Brazil-Nut forest (17%). Resprouting capacity was higher in the crop field, as Brazil-Nut plants recovered after fire episodes, with most plants resprouting more than one shoot. Some Trees in the crop field began to produce flowers and fruits at 9-10 years. We showed that B. excelsa juveniles are light-demanding, with higher survival and growth under conditions of high light exposure. We suggest the use of Brazil-Nut Trees for reforestation, restoration of degraded lands and enrichment of secondary vegetation, as long as an adequate management is adopted (e.g., maintaining plants exposed to direct sunlight and control of competing pioneer species).
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Human Influence on the Regeneration of the Brazil Nut Tree (Bertholletia excelsa Bonpl., Lecythidaceae) at Capanã Grande Lake, Manicoré, Amazonas, Brazil
Human Ecology, 2015Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:This study examines the population structure and regeneration of Brazil Nut tree ( Bertholletia excelsa ) populations at sites subjected to extractive activities in the Capanã Grande Lake Extractive Reserve (Rio Madeira, Amazonas, Brazil). We analyze correlations between three regeneration levels (seedling, sapling and juvenile density) and seven possible explicatory variables related to vegetation structure and human action. The tested vegetation structure variables include adult tree density, crown area, basal area, canopy openness, and fruits opened by agoutis. We also test the time of human use and distance from residences as possible explicatory variables. The density values of the Brazil Nut stands in the region are high (12.5 tree/ha), with 60 % of Trees having a diameter at breast height (DBH) > 80 cm. The mean potential regeneration (24.8 seedlings/ha), pre-established regeneration (4.4 saplings/ha) and established regeneration (3.2 juveniles/ha) values are high compared to other Brazil Nut tree populations and tend to be greater in the “intensively used” stands, defined as sites where human presence during the year is more frequent. The time of human use and the density of adult Brazil Nut Trees are the variables that best correlate with established regeneration (density of juveniles). The number of juveniles/adult Brazil Nut Trees is five times higher in intensively used stands than in those moderately used. These results suggest that extractive activities and disturbances in the understory caused by human presence may favor (intentionally or not) regeneration of Brazil Nut Trees in more-frequently used stands. The data support the concept, frequently suggested in the literature, that aggregations of Brazil Nut Trees could be a consequence of the activities of Amerindian populations.
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age and growth patterns of brazil Nut Trees bertholletia excelsa bonpl in amazonia brazil
Biotropica, 2015Co-Authors: Jochen Schongart, Rogerio Gribel, Sinomar Ferreira Da Fonsecajunior, Torbjørn HaugaasenAbstract:Various techniques have been used to estimate the age of Brazil Nut Trees (Bertholletia excelsa Bonpl.), but these techniques produce large discrepancies. Here, we first verified that two individuals of known ages from a plantation in central Amazonia, Brazil, have a congruent number of growth rings. The indexed average tree-ring curve was significantly correlated with total precipitation during the rainy season (November–June) over a 50-yr period, confirming the annual nature of the tree rings. Second, we analyzed Brazil Nut Trees from two populations in the Trombetas (eastern Amazon) and Purus (central Amazon) regions, performing tree-ring analysis to estimate tree age and diameter increment rates. We compared age–diameter relationships, mean passage time through 10-cm diameter size classes, and growth trajectories of individual Trees. The maximum age of Brazil Nut Trees analyzed was 361 yr in the Purus and 401 yr in the Trombetas. Trees at the Purus site had higher mean diameter increment rates and showed more variation compared to Trees at the Trombetas site. Individual growth trajectories show that the majority of Trees attained the canopy by direct growth, while a smaller number passed through one release or one suppression event before becoming established in the canopy. None of the Trees passed through multiple release and suppression events. The age estimations presented here are comparable to previous tree-ring analyses for the species, and the observed growth patterns support earlier work indicating B. excelsa as a gap-dependent tree species. Resumo Varias tecnicas vem sido utilizadas para se estimar a idade de Castanheiras-do-Para (Bertholletia excelsa Bonpl.). Entretanto, diferentes metodos apresentaram grande discrepâncias em relacao as estimativas das idades. No presente estudo, primeiramente verificamos um numero congruente de aneis de crescimento de dois individuos com idades conhecidas pertencentes a uma plantacao na Amazonia Central, Brasil. A curva media indexada dos aneis de crescimento apresentou uma relacao significativa com a precipitacao total durante a estacao chuvosa (novembro a junho) ao longo de um periodo de 50 anos, confirmando a natureza anual dos aneis das arvores. Posteriormente, analisamos os aneis de crescimento a fim de estimar a idade das arvores da Castanheiras-do-Para e as taxas de incremento de madeira em duas populacoes: uma na regiao do rio Trombetas (Amazonia Oriental) e outra no rio Purus (Amazonia Central). Nestes dois locais, avaliamos as relacoes entre idade e diâmetro, o tempo medio para avancarem pelas classes de tamanho de 10 cm de diâmetro e as trajetorias de crescimento individual das arvores. A idade maxima das Castanheiras-do-Para analisadas foi de 361 anos no Purus, e de 401 anos no Trombetas. As taxas de incremento diametrico medio foram altas e mais variaveis no Purus do que no Trombetas. As trajetorias de crescimento individual mostraram que a maioria das arvores atingiu o dossel por crescimento direto, enquanto um numero menor passou por um evento de liberacao ou supressao antes de se estabelecer no dossel. Nenhuma das arvores passou por eventos multiplos de liberacao ou supressao. As estimativas de idade apresentadas aqui sao comparaveis as analises anteriores de aneis de crescimento para a especie e os padroes de crescimento observados corroboram estudos anteriores indicando que a Castanheira-do-Para e uma especie arborea dependente de clareiras.
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the regeneration of brazil Nut Trees in relation to Nut harvest intensity in the trombetas river valley of northern amazonia brazil
Forest Ecology and Management, 2012Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:Abstract This study examined the harvest of Nuts from Brazil Nut Trees (Bertholletia excelsa) in the valley of the Trombetas River, a 760-km tributary on the northern bank of the Amazon River in Para state, Brazil. The region is characterised by old-growth forests dominated by Brazil Nut Trees. Demographic data were obtained from twenty-five 50-m × 1000-m transects with different harvest intensities (total area = 125 ha) established approximately along the trails used by Brazil Nut harvesters. For each transect, correlations were calculated between regeneration indicators (seedling, sapling, and juvenile densities) and potential ecological and demographic variables. The Brazil Nut populations in the region were characterised by a low proportion of juveniles (7.8% of Trees had a 10 cm 100 cm), and a tendency towards old growth (25.5% of Trees had a DBH > 160 cm). There were no seedlings in 52% of the transects, and 80% of the transects had no saplings. The low regeneration levels observed were independent of both harvest intensity and the dispersive activity of agoutis. An analysis of the regeneration indicators and the possible explanatory variables showed that harvests were not responsible for the low regeneration levels observed in the region. Furthermore, in areas with shorter distances between the points of harvest and first transport, the densities of saplings and juveniles were greater. We conclude that the restrictions on Brazil Nut harvesting that are intended to improve the regeneration of Brazil Nut Trees are of little or no value. We propose the implementation of compensatory measures involving local communities and the promotion of seedling enrichment in gaps, forest edges, and disturbed areas, with the goal of promoting the growth of new generations of Brazil Nut Trees in the region.
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seed dispersal of the brazil Nut tree bertholletia excelsa by scatter hoarding rodents in a central amazonian forest
Journal of Tropical Ecology, 2010Co-Authors: Joanne Tuck M Haugaasen, Torbjørn Haugaasen, Rogerio Gribel, Carlos A Peres, Per WeggeAbstract:We know surprisingly little about the fate of seeds of the Brazil Nut tree (Bertholletia excelsa) under natural conditions. Here we investigate seed removal, predation and caching of Brazil Nuts by scatter-hoarding rodents in the wet and dry seasons, based on an experimental approach using 900 thread-marked seeds. We tracked the fate of seeds handled by these animals to examine how seasonal food availability may influence caching rates, dispersal distances and cache longevity. Most seeds exposed to dispersal trials were removed by scatter-hoarders during the first week in both seasons and seeds were generally buried intact in single-seeded caches within 10 m of seed stations. Seeds were removed significantly faster and buried at greater distances during the dry season. The proportion of seeds buried intact was considerably higher in the wet season (74.4%) than in the dry season (38.2%). Most (99.4%) of the 881 primary caches monitored were recovered, but these had a significantly shorter lifetime in the dry season. Our results show that rodents are highly skilled at retrieving buried Brazil Nuts and that caching behaviour appears to be affected by seasonal resource abundance. Reduced seed availability due to intensive harvest could potentially create a dry-season scenario where most seeds succumb to pre-dispersal predation, thereby adversely affecting the natural regeneration of Brazil Nut Trees.
Torbjørn Haugaasen - One of the best experts on this subject based on the ideXlab platform.
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age and growth patterns of brazil Nut Trees bertholletia excelsa bonpl in amazonia brazil
Biotropica, 2015Co-Authors: Jochen Schongart, Rogerio Gribel, Sinomar Ferreira Da Fonsecajunior, Torbjørn HaugaasenAbstract:Various techniques have been used to estimate the age of Brazil Nut Trees (Bertholletia excelsa Bonpl.), but these techniques produce large discrepancies. Here, we first verified that two individuals of known ages from a plantation in central Amazonia, Brazil, have a congruent number of growth rings. The indexed average tree-ring curve was significantly correlated with total precipitation during the rainy season (November–June) over a 50-yr period, confirming the annual nature of the tree rings. Second, we analyzed Brazil Nut Trees from two populations in the Trombetas (eastern Amazon) and Purus (central Amazon) regions, performing tree-ring analysis to estimate tree age and diameter increment rates. We compared age–diameter relationships, mean passage time through 10-cm diameter size classes, and growth trajectories of individual Trees. The maximum age of Brazil Nut Trees analyzed was 361 yr in the Purus and 401 yr in the Trombetas. Trees at the Purus site had higher mean diameter increment rates and showed more variation compared to Trees at the Trombetas site. Individual growth trajectories show that the majority of Trees attained the canopy by direct growth, while a smaller number passed through one release or one suppression event before becoming established in the canopy. None of the Trees passed through multiple release and suppression events. The age estimations presented here are comparable to previous tree-ring analyses for the species, and the observed growth patterns support earlier work indicating B. excelsa as a gap-dependent tree species. Resumo Varias tecnicas vem sido utilizadas para se estimar a idade de Castanheiras-do-Para (Bertholletia excelsa Bonpl.). Entretanto, diferentes metodos apresentaram grande discrepâncias em relacao as estimativas das idades. No presente estudo, primeiramente verificamos um numero congruente de aneis de crescimento de dois individuos com idades conhecidas pertencentes a uma plantacao na Amazonia Central, Brasil. A curva media indexada dos aneis de crescimento apresentou uma relacao significativa com a precipitacao total durante a estacao chuvosa (novembro a junho) ao longo de um periodo de 50 anos, confirmando a natureza anual dos aneis das arvores. Posteriormente, analisamos os aneis de crescimento a fim de estimar a idade das arvores da Castanheiras-do-Para e as taxas de incremento de madeira em duas populacoes: uma na regiao do rio Trombetas (Amazonia Oriental) e outra no rio Purus (Amazonia Central). Nestes dois locais, avaliamos as relacoes entre idade e diâmetro, o tempo medio para avancarem pelas classes de tamanho de 10 cm de diâmetro e as trajetorias de crescimento individual das arvores. A idade maxima das Castanheiras-do-Para analisadas foi de 361 anos no Purus, e de 401 anos no Trombetas. As taxas de incremento diametrico medio foram altas e mais variaveis no Purus do que no Trombetas. As trajetorias de crescimento individual mostraram que a maioria das arvores atingiu o dossel por crescimento direto, enquanto um numero menor passou por um evento de liberacao ou supressao antes de se estabelecer no dossel. Nenhuma das arvores passou por eventos multiplos de liberacao ou supressao. As estimativas de idade apresentadas aqui sao comparaveis as analises anteriores de aneis de crescimento para a especie e os padroes de crescimento observados corroboram estudos anteriores indicando que a Castanheira-do-Para e uma especie arborea dependente de clareiras.
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seed dispersal of the brazil Nut tree bertholletia excelsa by scatter hoarding rodents in a central amazonian forest
Journal of Tropical Ecology, 2010Co-Authors: Joanne Tuck M Haugaasen, Torbjørn Haugaasen, Rogerio Gribel, Carlos A Peres, Per WeggeAbstract:We know surprisingly little about the fate of seeds of the Brazil Nut tree (Bertholletia excelsa) under natural conditions. Here we investigate seed removal, predation and caching of Brazil Nuts by scatter-hoarding rodents in the wet and dry seasons, based on an experimental approach using 900 thread-marked seeds. We tracked the fate of seeds handled by these animals to examine how seasonal food availability may influence caching rates, dispersal distances and cache longevity. Most seeds exposed to dispersal trials were removed by scatter-hoarders during the first week in both seasons and seeds were generally buried intact in single-seeded caches within 10 m of seed stations. Seeds were removed significantly faster and buried at greater distances during the dry season. The proportion of seeds buried intact was considerably higher in the wet season (74.4%) than in the dry season (38.2%). Most (99.4%) of the 881 primary caches monitored were recovered, but these had a significantly shorter lifetime in the dry season. Our results show that rodents are highly skilled at retrieving buried Brazil Nuts and that caching behaviour appears to be affected by seasonal resource abundance. Reduced seed availability due to intensive harvest could potentially create a dry-season scenario where most seeds succumb to pre-dispersal predation, thereby adversely affecting the natural regeneration of Brazil Nut Trees.
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A Lepidopteran defoliator attack on Brazil Nut Trees (Bertholletia excelsa) in Central Amazonia, Brazil
Biotropica, 2009Co-Authors: Torbjørn HaugaasenAbstract:This paper describes a severe outbreak of a Lepidopteran defoliator, Lusura altrix (Stoll 1782), on Brazil Nut Trees in Central Amazonia. The pest outbreak appeared to succeed abnormal weather conditions, and defoliation was sufficient to disrupt normal phenological patterns.
Karline R L Janmaat - One of the best experts on this subject based on the ideXlab platform.
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sooty mangabeys scavenge on Nuts cracked by chimpanzees and red river hogs an investigation of inter specific interactions around tropical Nut Trees
American Journal of Primatology, 2018Co-Authors: Bryndan O C M Van Pinxteren, Giulia Sirianni, Paolo Gratton, Marielyne Despreseinspenner, Martijn Egas, Hjalmar S Kuhl, Juan Lapuente, Amelia Meier, Karline R L JanmaatAbstract:Carrion scavenging is a well-studied phenomenon, but virtually nothing is known about scavenging on plant material, especially on remnants of cracked Nuts. Just like meat, the insides of hard-shelled Nuts are high in energetic value, and both foods are difficult to acquire. In the Tai forest, chimpanzees (Pan troglodytes) and red river hogs (Potamochoerus porcus) crack Nuts by using tools or strong jaws, respectively. In this study, previously collected non-invasive camera trap data were used to investigate scavenging by sooty mangabeys (Cercocebus atys), two species of Guinea fowl (Agelestres meleagrides; Guttera verreauxi), and squirrels (Scrunidae spp.) on the Nut remnants cracked by chimpanzees and red river hogs. We investigated how scavengers located Nut remnants, by analyzing their visiting behavior in relation to known Nut-cracking events. Furthermore, since mangabeys are infrequently preyed upon by chimpanzees, we investigated whether they perceive an increase in predation risk when approaching Nut remnants. In total, 190 Nut-cracking events were observed in four different areas of Tai National Park, Ivory Coast. We could confirm that mangabeys scavenged on the Nuts cracked by chimpanzees and hogs and that this enabled them to access food source that would not be accessible otherwise. We furthermore found that mangabeys, but not the other species, were more likely to visit Nut-cracking sites after Nut-cracking activities than before, and discuss the potential strategies that the monkeys could have used to locate Nut remnants. In addition, mangabeys showed elevated levels of vigilance at the chimpanzee Nut-cracking sites compared with other foraging sites, suggesting that they perceived elevated danger at these sites. Scavenging on remnants of cracked Nuts is a hitherto understudied type of foraging behavior that could be widespread in nature and increases the complexity of community ecology in tropical rainforests.
Eike Luedeling - One of the best experts on this subject based on the ideXlab platform.
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climate change affects winter chill for temperate fruit and Nut Trees
PLOS ONE, 2011Co-Authors: Eike Luedeling, Evan H Girvetz, Mikhail A Semenov, Patrick H BrownAbstract:Background Temperate fruit and Nut Trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. Methodology/Principal Findings We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the “Dynamic Model” and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. Conclusions/Significance The extent of projected changes in winter chill in many major growing regions of fruits and Nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.
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climate change affects winter chill for temperate fruit and Nut Trees
PLOS ONE, 2011Co-Authors: Eike Luedeling, Evan H Girvetz, Mikhail A Semenov, Patrick O BrownAbstract:Author(s): Luedeling, Eike; Girvetz, Evan H; Semenov, Mikhail A; Brown, Patrick H | Abstract: BackgroundTemperate fruit and Nut Trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields.Methodology/principal findingsWe estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG.Conclusions/significanceThe extent of projected changes in winter chill in many major growing regions of fruits and Nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.
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a global analysis of the comparability of winter chill models for fruit and Nut Trees
International Journal of Biometeorology, 2011Co-Authors: Eike Luedeling, Patrick H BrownAbstract:Many fruit and Nut Trees must fulfill a chilling requirement to break their winter dormancy and resume normal growth in spring. Several models exist for quantifying winter chill, and growers and researchers often tacitly assume that the choice of model is not important and estimates of species chilling requirements are valid across growing regions. To test this assumption, Safe Winter Chill (the amount of winter chill that is exceeded in 90% of years) was calculated for 5,078 weather stations around the world, using the Dynamic Model [in Chill Portions (CP)], the Chilling Hours (CH) Model and the Utah Model [Utah Chill Units (UCU)]. Distributions of the ratios between different winter chill metrics were mapped on a global scale. These ratios should be constant if the models were strictly proportional. Ratios between winter chill metrics varied substantially, with the CH/CP ratio ranging between 0 and 34, the UCU/CP ratio between −155 and +20 and the UCU/CH ratio between −10 and +5. The models are thus not proportional, and chilling requirements determined in a given location may not be valid elsewhere. The Utah Model produced negative winter chill totals in many Subtropical regions, where it does not seem to be useful. Mean annual temperature and daily temperature range influenced all winter chill ratios, but explained only between 12 and 27% of the variation. Data on chilling requirements should always be amended with information on the location and experimental conditions of the study in which they were determined, ideally including site-specific conversion factors between winter chill models. This would greatly facilitate the transfer of such information across growing regions, and help prepare growers for the impact of climate change.
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sensitivity of winter chill models for fruit and Nut Trees to climatic changes expected in california s central valley
Agriculture Ecosystems & Environment, 2009Co-Authors: Eike Luedeling, Minghua Zhang, Volker Luedeling, Evan H GirvetzAbstract:Abstract Many fruit and Nut crops require cold temperatures in winter to break dormancy. Quantifying this chilling requirement and selecting appropriate cultivars for the climate of a growing region is crucial for successful cultivation of such crops. Several models exist to quantify winter chill, and each growing region uses a model that has been shown to perform well under local climatic conditions. We tested the sensitivity of four commonly used chilling models to projected climatic change likely to affect fruit and Nut production in the near future. For six sites in California's Central Valley, we generated 100 years of synthetic hourly weather records, representing climatic conditions in 1950, 2000 and projected temperatures in 2041–2060 derived from three IPCC-AR4 General Circulation Models (GCMs; CSIRO, HadCM3 and MIROC; A2 greenhouse gas emissions scenario). Mean winter chill for each site and year was calculated using the Chilling Hours, Utah, Positive Utah and Dynamic models. All chilling models predicted substantial decreases in winter chill at all sites, but the extent of these decreases varied depending on the model used. Across all sites between 1950 and 2050, mean chilling was predicted to decrease by 33% (Chilling Hours), 26% (Utah Model), 16% (Dynamic Model) and 14% (Positive Utah Model). Research efforts are needed to identify the most appropriate chilling model for preparing fruit and Nut growers for the imminent effects of climate change.
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climatic changes lead to declining winter chill for fruit and Nut Trees in california during 1950 2099
PLOS ONE, 2009Co-Authors: Eike Luedeling, Minghua Zhang, Evan H GirvetzAbstract:Background Winter chill is one of the defining characteristics of a location's suitability for the production of many tree crops. We mapped and investigated observed historic and projected future changes in winter chill in California, quantified with two different chilling models (Chilling Hours, Dynamic Model). Methodology/Principal Findings Based on hourly and daily temperature records, winter chill was modeled for two past temperature scenarios (1950 and 2000), and 18 future scenarios (average conditions during 2041–2060 and 2080–2099 under each of the B1, A1B and A2 IPCC greenhouse gas emissions scenarios, for the CSIRO-MK3, HadCM3 and MIROC climate models). For each scenario, 100 replications of the yearly temperature record were produced, using a stochastic weather generator. We then introduced and mapped a novel climatic statistic, “safe winter chill”, the 10% quantile of the resulting chilling distributions. This metric can be interpreted as the amount of chilling that growers can safely expect under each scenario. Winter chill declined substantially for all emissions scenarios, with the area of safe winter chill for many tree species or cultivars decreasing 50–75% by mid-21st century, and 90–100% by late century. Conclusions/Significance Both chilling models consistently projected climatic conditions by the middle to end of the 21st century that will no longer support some of the main tree crops currently grown in California, with the Chilling Hours Model projecting greater changes than the Dynamic Model. The tree crop industry in California will likely need to develop agricultural adaptation measures (e.g. low-chill varieties and dormancy-breaking chemicals) to cope with these projected changes. For some crops, production might no longer be possible.
Lucia Helena De Oliveira Wadt - One of the best experts on this subject based on the ideXlab platform.
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strong el nino reduces fruit production of brazil Nut Trees in the eastern amazon
Acta Amazonica, 2021Co-Authors: Dayane Nathalia Barbosa Pastana, Lucia Helena De Oliveira Wadt, Erica De Souza Modena, Ezaquiel De Souza Neves, Lucieta Guerreiro Martorano, A C Liraguedes, Rafael Lucas Figueiredo De Souza, Felipe Felix Costa, Anderson Pedro Bernardina Batista, Marcelino Carneiro GuedesAbstract:ABSTRACT The Brazil-Nut tree (Bertholletia excelsa) is native to the Amazon rainforest, and its fruit production varies naturally with climatic conditions. Our aim was to evaluate the temporal variation in Brazil-Nut production associated with climatic variables, including the strong El Nino of 2015/2016. The study was carried out in two 9-ha permanent plots in the northeastern Brazilian Amazon from 2007 to 2018: one in forest (12-year monitoring) and the other in savannah/forest transition (eight years). Overall, we monitored fruit production of 205 Trees with diameter at breast height ≥ 50 cm. Annual fruit production was related to temporal series (2005-2018) of climatic data (the Oceanic Nino Index; and precipitation and air temperature from two local meteorological stations). Average fruit production per tree in 2017 was eight times lower than in 2015 and two times lower than the general average for both sites, and was significantly associated to the El Nino of 2015/2016, that increased average maximum monthly temperature and reduced the precipitation in the region, extending the dry season from three to six months. Years with higher and lower fruit production per tree coincided in both sites. Annual fruit production was significantly and negatively correlated with thermal anomalies that occurred in the third semester prior to harvest monitoring. Years with higher production were related with predominance of neutrality or the La Nina phenomenon at the global scale, and higher rainfall at the local scale. The relationship of fruit production with climate was independent of the local habitat.
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Pollen and seed dispersal of Brazil Nut Trees in the southwestern Brazilian Amazon
2018Co-Authors: Karina Martins, T. De ,campos, Raifanny Da Silva Oliveira Dos Santos, Lucia Helena De Oliveira WadtAbstract:ABSTRACT Pollen and seed dispersal patterns greatly influence the spatial distribution of plant genetic diversity. Microsatellite-based parentage analysis provides accurate estimates of contemporary gene dispersal. Although most tropical Trees have been shown to exhibit widespread pollen dispersal, few studies have estimated contemporary gene dispersal after seedling establishment. Bertholletia excelsa (Lecythidaceae) is pollinated by large-bodied bees, while previous seed-tracking experiments suggest their seeds are mainly dispersed across very short distances by scatter-hoarding rodents, who primarily act as seed predators. Here we used parentage analysis to provide contemporary estimates of pollen and seed dispersal in B. excelsa recruits. We examined six 25-ha plots located in two natural stands in the Acre River valley, in the southwestern Brazilian Amazon. We used 11 microsatellite markers to estimate genetic diversity and fixation index parameters in adults, seedlings and saplings. Genetic diversity was moderate and did not differ across size classes or sampling locations. We assigned pollen and seed parents for < 20% of the recruits, indicating that most events of realized gene flow occurred beyond our 25-ha plots. Only 10 parentage assignments were confirmed with 80% confidence. Pollen distance ranged from 33 to 372 m and seed dispersal from 58 to 655 m. Actual seed-dispersal distances were far greater than the estimates obtained in previous seed-tracking experiments. Thus, studies encompassing larger sampling areas are necessary to determine a more representative spatial scale of B. excelsa’s pollen and seed dispersal capacity in natural stands.
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natural variation of selenium in brazil Nuts and soils from the amazon region
Chemosphere, 2017Co-Authors: E C Silva, Lucia Helena De Oliveira Wadt, Katia Emidio Da Silva, Ricardo M Lima, K D Batista, Marcelino Carneiro Guedes, G S Carvalho, Teotonio Soares De Carvalho, Andre Rodrigues Dos Reis, Guilherme LopesAbstract:Brazil Nut tree (Bertholletia excelsa) is native of the Amazon rainforest. Brazil Nuts are consumed worldwide and are known as the richest food source of selenium (Se). Yet, the reasoning for such Se contents is not well stablished. We evaluated the variation in Se concentration of Brazil Nuts from Brazilian Amazon basin, as well as soil properties, including total Se concentration, of the soils sampled directly underneath the Trees crown, aiming to investigate which soil properties influence Se accumulation in the Nuts. The median Se concentration in Brazil Nuts varied from 2.07 mg kg-1 (in Mato Grosso state) to 68.15 mg kg-1 (in Amazonas state). Therefore, depending on its origin, a single Brazil Nut could provide from 11% (in the Mato Grosso state) up to 288% (in the Amazonas state) of the daily Se requirement for an adult man (70 μg). The total Se concentration in the soil also varied considerably, ranging from <65.76 to 625.91 μg kg-1, with highest Se concentrations being observed in soil samples from the state of Amazonas. Se accumulation in Brazil Nuts generally increased in soils with higher total Se content, but decreased under acidic conditions in the soil. This indicates that, besides total soil Se concentration, soil acidity plays a major role in Se uptake by Brazil Nut Trees, possibly due to the importance of this soil property to Se retention in the soil.
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sustainable forest use in brazilian extractive reserves natural regeneration of brazil Nut in exploited populations
Biological Conservation, 2008Co-Authors: Lucia Helena De Oliveira Wadt, Karen A Kainer, Christina L Staudhammer, R O P SerranoAbstract:Abstract The emergence of Brazilian extractive reserves reinforced the notion that sustainable forest use could play a central role in conservation. Brazil Nut is considered a model non-timber product for promoting conservation through use. Demographic studies, however, have demonstrated differential impacts of Nut harvest on Brazil Nut population structure. Comparing three populations with different forest use histories, degrees of road access, and recent levels of Nut harvest, we asked: (1) Are they exhibiting regeneration failure? and (2) Are seedling/sapling densities explained by adult Brazil Nut structure, fruit fate and/or overall forest structure? We installed four 9-ha plots in each site to census Brazil Nut Trees ⩾10 cm dbh, and within each plot, 36 subplots (25 × 25 m each) to quantify regeneration, overall forest structure, and open and closed fruit counts. Approximately 29–55% of fruits was unharvested, and more than 90% of these was opened by scatterhoarding dispersers. Population structure approximated a reverse-J size class distribution, with seedling densities varying from 3.2 to 5.8 individuals ha −1 . We conclude that within the current harvest context, regeneration is sufficient for population persistence in our sites, at least over the medium term. The socioeconomics of sustainably managing Brazil Nut is the greater challenge, involving interlinked competitive land uses, Nut quality, and substantial increases in local income from harvest. Some of these challenges are being addressed in Brazil, Bolivia and Peru, providing hope that this cornerstone extractive species will continue to play a prominent role in the ecological and economic landscape of Amazonia.
